A Lab Group : Lab Report Essay
Biology Lab 10501
November 30th, 2016
Lab Group: Drew Garza, Brock Morgan, Christian Chen, Daniel Lee.
INTRODUCTION Mutations are permanent changes in DNA sequence that makes up a certain gene that are caused by environmental factors or when DNA is copied in the replication phase. Mutations can range in various sizes and can affect any part of the DNA sequence. In our lab we dealt with Ethyl Methanesulfonate (EMS) and Sega (2015, p.1) stated that “Ethyl Methanesulfonate is a monofunctional methylating agent that has been found to be mutagenic in a wide variety of genetic test systems from viruses to mammals.” In addition (Cameo, p.1) stated that “ EMS can cause multiple symptoms such as vomiting, nausea, and problems in the central nervous system.” In our lab we used the his- S. typhimurium bacterial strain TA1535 in our screen for mutagens. TA1535 has acquired a missense mutations in the hisG gene which leads to leucine to proline amino acid substitutions. The result of this mutation causes it to be auxotrophic, meaning it cannot survive on its own with histidine. However, the bacteria can be capable to survive on its own in the absence of histidine if it undergoes reversions (mutations that grant them the ability to to produce histidine). In return, we can use the reversion rate to measure and calculate the mutagenic properties of our chemical Ethyl Methanesulfonate.…